Generally, a substrate processing system includes process modules for performing plasma processing on a semiconductor wafer (hereinafter simply referred to as a “wafer” (that is, a substrate) using plasma, and a transfer module or a loader module for conveying wafers between the corresponding process modules and Front Opening Unified Pods (FOUPs) (that is, containers for accommodating wafers). In the substrate processing system, particles may adhere to wafers when the plasma processing is performed on the wafers or when the wafers are conveyed. The adhered particles cause defects in semiconductor devices fabricated using the wafers. Accordingly, there is a need to prevent the particles from adhering to the wafers.
Particles are generated due to various factors, such as a mechanical contact between a wafer and a component part and a chemical reaction between a processing gas and some other material. In the substrate processing system, a large number of semiconductor devices are fabricated by performing plasma processing on a lot of wafers. If the occurrence factors of particles are not removed, the yield of the semiconductor devices becomes extremely low. Accordingly, in the substrate processing system, it is very important to determine the occurrence factors of particles and to remove the corresponding occurrence factors.
Accordingly, there have been proposed various conventional methods of fully testing particles adhered to a wafer and detecting the occurrence factors of particles based on the test results. In more detail, there was proposed a method of easily detecting the occurrence factors of particles by acquiring the distributions of the particles in a wafer in the form of an alien substance map and by automatically classifying the particles in the corresponding alien substance map (for example, refer to Japanese Patent Application Publication No. H8-189896).
However, in order to determine the occurrence factors of particles based on the classification results of the particles, there is a need for a knowledgeable technician who is familiar with the occurrence factors of particles (for example, a technician who works for a manufacturer that manufactures a substrate processing system), even though the corresponding classification results appear on the alien substance map in the above-described method.
Furthermore, the substrate processing system is installed not in the factory of the manufacturer that manufactures the corresponding substrate processing system but in the factory of a customer who purchases the corresponding substrate processing system. Thus, the manufacturer's technician cannot always be near the substrate processing system. Consequently, when particles adhere to a wafer, a person who first determines the occurrence factors of particles is the customer's technician.
The corresponding customer's technician generally does not have detailed knowledge of the occurrence factors of particles. Accordingly, although the results of the classification of the particles are obtained, there is a problem in that the occurrence factors of particles cannot be accurately determined. For this reason, strange results, such as a reduction in the rate of operation of the substrate processing system, come about because the corresponding substrate processing system is stopped until the manufacturer's technician arrives at the customer's factory.